exc.py: Generalize ExTracker to not just print the # of errors at exit. Instead, provide an exit() method that the ExTracker creator can call at exit to set the exit status to the # of errors. This fixes the Python bug where a benign error message was printed if SystemExit was raised in an atexit function.
exc.py: Generalize ExTracker to not just print the # of errors at exit. Instead, provide an exit() method that the ExTracker creator can call at exit to set the exit status to the # of errors. This fixes the Python bug where a benign error message was printed if SystemExit was raised in an atexit function.